根据江苏省农用地22个标准样地的7种重金属元素含量测定结果,应用TWINSPAN分类、CCA排序的多元统计方法,对江苏农用地耕作层土壤重金属元素含量格局和影响因子进行了定量分析。研究结果表明,江苏耕作层土壤重金属元素含量整体特征具有明显的沿经济发展梯度(苏南-苏中-苏北)的递减格局。空间位置、人类活动强度、土壤理化性质是控制梯度分布格局重要的环境因素,通过变量分离,空间变量解释的部分占21.5%,人为活动变量解释部分占17.9%,理化性质变量解释部分占17.5%,三组变量总解释量占56.9%,不能解释部分占43.1%。人类活动与空间位置因素一起可以综合反映江苏经济发展的空间梯度,其占了总解释量的69.2%,经济发展梯度对农用地重金属元素含量有着深刻的影响。

Seven kinds of heavy metals content at 22 norm sample plots were determined in Jiangsu Province. Using heavy metals content data, we analyzed the pattern of heavy metals and its influencing factor by TWINSPAN and CCA. The results showed that the distribution of heavy metals in Jiangsu Province was different obviously. Entire distribution feature of heavy metals distribution had a clear gradient with "Subei North Jiangsu-Suzhong (Central Jiangsu)-Sunan (South Jiangsu)". The elements which controlled the entire feature distribution of heavy metals were Hg, Cd and Cu in the Sunan region, Pb, Cr and Ni in the Suzhong and region Subei district. Spatial location, soil physicochemical property and human active intensive were the most important influencing factors which controlled the distribution pattern of heavy metals in Jiangsu. The explanation of three influencing variations accounted for 56.9%, of which the explanation location variation independently was 21.5%, soil physicochemical property was 17.5%, and the human active intensive is 17.9%, but 43.1% could not be explained. This research showed that the spatial distribution pattern of Theavy metals in soil was affected deeply by economic development gradient in Jiangsu Province. The method of WINSPAN and CCA is good for analysis the relations between heavy metals content and influence variations, and it may be a potential method for soil environment research.